Effects Of Growth Hormone On Acute Hepatic Failure In Rats And Its Mechanism

Objective Acute Hepatic Failure is a serious disease with higher motality inwhich much hepatocyte was damaged and followed by hepatic encephalopathywithin short time.The mechanism of AHF is very complicated and most study suggestthat the disorder of immunology play a pivotal role in AHF. Although manytreatments (therapies)have been used, however they are not successful in reducing themortality of AHF. Growth hormone (GH) is a potent anabolic hormone, Insulin-likegrowth factor 1 (IGF-1) mediates the anabolic elect of GH. Many studies have shownthat GH can improve protein synthesis and liver regeneration, Moreover, GH haveimmunostimulatory efects. So GH can improve nutritional stataus and protect liverfunction which maybe increase the survival rate of AHF patients. The aim of thisstudy was to investigate the effect of GH on a rat model of Acute Hepatic Failure.Methods Male Wister rats, weighting 180g-220g were used. The rats were keptin animal facilities for 1 week prior to initiateing the experiments to allowacclimation. Then they were randomly devided into 4 groups: the normal controllgroup (no therapy, group A) was killed at the beginning of experiment at 24 hours,model controll(physiological saline, group B)and high,low dose rhGH(4 or 1U/kg ofbody weight per day respectively, group C and D), The rats were subcutaneouslyadministered rhGH or physiological saline for 6 days. After fasting for 12 hours therats of groupB,C,D were administered D-galactosamin (D-GaIN) intraperitoneally ata dose of 1200mg/kg 6 hours after the last administration of rhGH orphysiological saline,D-GaiN was freshly dissolved in physiological saline (1:10 ) and ajusted to PH 7.0. All the survival rats were killed at day 7 after D-GalNinjection.Levels ofALT, AST, TBIL,IL-18 in the rats serum were measured and liverspecimens of rats were observed under light microscopy. Data were expressed as meanvalue-4- standard deviation and assessed by the One-Way ANOVA test. All statisticswere carried out in computer with SPSS 13.0 software.A probability value＜0.05 wasconsider as statistically significant.Results The serum ALT, AST, TBIL, IL-18 level in groupB,C,D have a markedincrease than group A at 24hours, 48 hours and 72 hours after administeringD-GaIN intraperitioneally (p＜0.05) and restored near to normal at day 7.Significant correlations were observed between IL-18 and hepatocyte damage, themore serious the rats, the more excessive production of IL-18.The serumALT,IL-18 level in rhGH group were decreased significantly than that of group B(p＜0.05), which in high dose rhGH was more lower than that of low dose rhGH(p＜0.05).Conclusion GH could improve the liver function in the rat model of AHF.GHmight play its efect by regulating the expression of cytokine..